Feed mechanism for sewing machines and the like



y 2, Nfv. CHRISTENSEN ET AL ,1

FEED MECHANISM FOR SEWING MACHINES AND THE LIKE Filed NOV. 29, 1935 2 Sheets-Sheet 1 FIG I- INVENTORS:

Norman VChristensen, Cum ems 6. 5mm 54 qwr 554mm;

TTORNEYS. 1

y 1939. N. v. CHRISTENSEN ET AL 2,156,525

FEED MECHANISM FOR SEWING MACHINES AND THE LIKE Filed Nov. 29, 1955 i 2 Sheets-Sheet 2' WITNESSES: INVENTORsi'.

Patented May 2, 1939 FEED MECHANISM FOR SEWING MACHINES AND THE LIKE.

Norman V. Christensen and Clarence C. Smith,

Chicago, and George Sauer, Berwyn, 111., assignors to Union Special Machine Company, Chicago, 1111., a corporation of Illinois Application November 29, 1935, Serial No. 51,992

12 Claims.

This invention relates to feed mechanism for sewing machines and the like, and particularly to a four-motion type of feed. The invention is especially concerned with the up and down movement of a feed-dog and its carrier, as well as with a combined actuation of the feed-dog for both horizontal and up-and-down motions. The invention also permits of adjusting one of such motions without materially affecting the other. While a feed mechanism having an eccentriccrank actuator of the strictly crank type has been herein illustrated and described, it will be understood that an eccentric-crank actuator of the eccentric type might equally well be used, and that still other types of rotary actuator could be employed.

Other features and advantages of the invention will appear from the following description of a species or form of embodiment thereof, and from the drawings,

In the drawings, Fig. I is a partial side view of a sewing-machine equipped with feed mechanism conveniently embodying our invention, certain parts being broken away or in vertical section.

Fig. II is a plan View of the feed mechanism, with certain parts broken away and in horizontal section as indicated by the line and arrows II-II in Fi I.

Fig. III is a side view of the feed mechanism from the right of Fig. I, with a part of the associated structure broken away and in section.

Fig, I shows a sewing machine with a needle Ill in a 'vertically reciprocating needle bar II, a presser foot l2, and a work support or bed l3 with a suitable opening for a feed-dog it. These parts may be of any suitable construction, and the needle bar I l and presser foot l2 may be operated in any suitable way.

The feed-dog l4 may be carried by a support or feed bar I5 shown as arranged approximately horizontal beneath the work support l3, the feeddog Hi being in the present instance (detachably) mounted near one end of said carrier l5. For convenience, this end of the carrier or feed-bar 15 may be distinguished as the forward end, without regard to the fact that with feed-dog teeth of the conformation shown, the work to be fed approaches from this end of the carrier. The rear end of the feed-bar I5 is supported for horizontal to and fro feeding movement, as by a feed rocker l6 pivoted to the feed bar at I? and mounted for oscillation about the axis of a shaft l8 fixedly supported beneath the work support 13, as in lugs [9 depending from the work support. The forwardend of the feed-bar I5 is supported and moved up and down by suitable mechanism pivoted thereto at 20, here shown as including a link 2| pivoted at 22 to the approximately horizontal arm of a rocker 24, which also comprises an upstanding arm 25 and a rock-shaft 2i interconnecting the arms. The rock-shaft 21 may be journaled in a bearing bracket 28 attached to the work support l3 at its lower side, as by screws 29.

As a source of motion for the feed-dog l4 and its carrier l5, there is an actuating or feed shaft 30 below the work support l3, journaled in suitable bearings in the frame 3! and provided with an eccentric-crank 32,-here shown as a crank in the strict sense, consisting of a crank pin 33 in a disc on the distal end of the shaft 30, speaking with reference to the point (beyond the limits -of Fig. II) where this shaft is driven. Rotary motionpreferably a constant unidirectional rotation, rather than an oscillation or an intermittent rotation-may be imparted to the shaft 33 and its actuator 32 in any suitable way. For high speeds, such a crank may be found preferable to an eccentric, because of the lower surface speed and lessened wear and danger of heating at the surface of the crank-pin 33. As shown, a spindle 34 for carrying parts of the stitch mechanism (not shown) below the work support l3 may be mounted in a bearing in the frame 3| and driven from the shaft 30 through gearing 35. The crank 32 drives a pitman-like member 31 which 'is in longitudinal sliding engagement with a transmitting member 38 arranged to oscillate as required by the vertical component of the rotary movement of the crankpin 33. As here shown, the sliding engagement between the members 31 and is telescopic, the pitman 3'1 sliding in a longitudinal bore in the member 38, freely but without side play.

The up and down movement of the feed-dog It and its carrier I5 is taken directly from the pitman 37. For this purpose, a link 43, shown as curved downward to clear the crank pin 33 and the surrounding head of the pitman 31, is pivoted to the pitman at 4| and is also pivoted at 42 to the upstanding arm 25 of the rocker 24. Through this operating connection comprising link 6, rocker 24, and link 2|,- the horizontal component of the rotary movement of the actuating means comprising eccentric crank 32 and pitman 31 is translated into up and down movement of carrier l5 and feed-dog M,

In the present instance, the horizontal to and fro feed movement of carrier l5 and feed-dog l4 are also derived from the actuating mechanism comprising eccentric-crank 32 and pitman 31. For this purpose, the member 38 in which pitman 3! slides is pivoted at 44 to the feed-rocker H5, at an intermediate point in its height between shaft l8 and carrier pivot H. The movement of member 38 is also guided and controlled by guide means pivoted thereto at 45, so as to afford a mobile fulcrum for said member 38, and shown in Figs. I and II as comprising a swinging link 46 pivoted at 41 to an adjustable supporting arm 48 mounted on one end of an adjusting shaft 49 journaled in suitable bearings in the frame 3|. Any suitable means (not shown) may be provided for turning and setting shaft 49 to the desired angular position, to control and vary the direction of travel of the fulcrum 45.

All of this mechanism, including crank 32, rockers l6 and 24, and feed bar I5, is mounted and arranged beneath the stitching end of the work support I3.

Through the mechanism comprising the member 38 and the feed rocker l1, etc., the vertical component of motion of the actuating means comprising crank 32 and pitman 31 is translated into substantially horizontal backward and forward movement of the carrier I and the feeddog I4. The setting of the supporting-arm 48 determines what proportion of this vertical movement shall be transmitted to the feed-dog M, i. e., if the supporting arm 48 were set in alignment or parallel with the member 38, scarcely any of the vertical motion would be transmitted to the feed-dog; while as the supporting arm 48 is swung upward from such a position of alignment toward its (limiting) full line position shown in Fig. I, the proportion of the vertical motion transmitted to the feed-dog is increased.

But the horizontal motion of crank 32 and pit-,

man 31 does not really affect the transmitting member 38 and the horizontal movement of the carrier or feed bar I5. It will be observed, also, that the adjustment of the horizontal motion of the feed-dog (derived from the vertical motion of the actuating means) has little or no practical efiect on the vertical motion of the feed-dog as derived from the horizontal motion of the actuating means.

The present invention relates to the means of imparting up-and-down motion to the feed-dog, and to its combination with that for imparting horizontal to-and-fro motion thereto. No claim is herein made to the particular mechanism for imparting horizontal motion to the feed-dog, in and by itself, since this forms the subject of application Serial No. 673,738, of George Sauer and Clarence C. Smith, filed May 31, 1933, and assigned to the assignee of this application.

Having thus described our invention, we claim:

1. In a sewing machine, the combination with a feed bar and a feed dog on its forward end, a single rotary feed actuator below and intermediate the ends of said feed bar, and means for transmitting feed motion from said actuator to said feed bar, of means connecting said actuator to the forward end of said feed bar, for transmitting lifting motion from the actuator to said forward end of said bar.

2. In a sewing machine, the combination with a feed bar and a feed dog on its forward end, a single rotary feed actuator, and means for transmitting feed motion from said actuator to the rear end of said feed bar, of an armed lifting rocker with a link connecting one of its arms to the forward end of said feed bar, and an operating connection from said actuator to the other arm of said lift rocker.

3. In a sewing machine, the combination with feed mechanism comprising a feed bar and its feed dog, a rotary feed actuator and a pitman directly operated thereby, and mobile guide means wherein the pitman slides to and fro, of operating connections from said guide means and said pitman to said feed bar, one for imparting feed motion to the feed bar, and the other for imparting lift motion thereto.

4. In a sewing machine, the combination of a feed bar and its feed dog, a rotary feed actuator with means and connections extending alongside but spaced from said feed bar for transmitting vertical and horizontal components of the motion of said actuator to opposite sides thereof, and there connected to the rear and forward ends of said feed bar to impart feed and lift motions thereto, respectively, the space between said feed bar and said oppositely extending connections affording room for stitch mechanism, and the space between the connections to the feed .bar affording free access under said bar to such stitch mechanism.

5. The combination with a sewing machine bed and support for the Work while being fed and sewed, and a rotary feed-actuating shaft extending along under said bed and work support, almost to the stitch point; of feed mechanism at the distal end of said shaft, under the stitching end of said work support, comprising a feed bar with its feed dog, and a rotary feed-actuator on the distal end of said shaft with means and connections extending alongside but spaced from said feed bar for transmitting feed and lift motions from said actuator to opposite sides thereof, and there connected to the opposite ends of said feed bar; the space between said feed bar and said oppositely extending connections affording room for stitch mechanism, and the space between the connections to the feed bar affording free access under said bar to such stitch mechanism.

6. The combination with feed mechanism comprising a feed bar and a feed dog on its forward end, a rotary feed actuator, means for translating the vertical component only of the rotary motion of said actuator into feed motion of said feed bar, and means for varying the motion derived from said vertical component; of means for translating the horizontal component of the rotary motion of said actuator into lift motion of the forward end of said feed bar, substantially unaffected by variation of the feed motion as aforesaid.

7. The combination with a sewing machine bed and support for the work while being fed and sewed, of a feed bar below said bed with a feed dog for the work thereon, a spindle under said bed and work support for carrying parts of a stitch-forming mechanism, a feed shaft extending alongside said spindle under said bed and work support, a rocker at the same side'of said spindle as said feed shaft, adjacent said feed bar, for imparting horizontal to and fro movements to said feed bar, a rocker support at the opposite side of said spindle, adjacent said feed bar, for imparting up and down movements to said feed bar, and means on said feed shaft, also adjacent said feed bar, and beneath the stitching end of said work support, for actuating the said rockers.

8. A feed mechanism of the character described comprising a feed dog and its carrier, means supporting one end of said carrier for substantially horizontal movement, a drive shaft and an eccentric-crank actuator thereon, a pitman actuated by said actuator and a member in longitudinal sliding engagement with said pitman and operatively connected to said carrier to reciprocate it horizontally, means affording a mobile fulcrum for said member, and an operating connection from said pitman to the other end of said carrier for moving the latter up and down.

9. A feed mechanism of the character described comprising a feed dog and its support or carrier, means supporting one end of said carrier for substantially horizontal movement, a drive shaft and an eccentric-crank actuator thereon, a pitman actuated by said crank and a member in longitudinal sliding engagement with said pitman and operatively connected to said carrier to reciprocate it horizontally, means aifording a mobile fulcrum for said member, a rocker having substantially upright and horizontal arms, a link connecting said upright arm to said pitman, and a link connecting said horizontal arm to the other end of said carrier.

10. A feed mechanism of the character described comprising a feed dog and its carrier, a rocker supporting one end of said carrier for substantially horizontal movement, a drive shaft and an eccentric-crank actuator thereon, a pitman actuated by said actuator and a member in longitudinal sliding engagement with said pitman and pivoted to said rocker, means affording a mobile fulcrum for said member adjustable to vary the direction of travel of the fulcrum and the consequent horizontal movement of the carrier, and an operating connection from said pitman to the other end of said carrier for moving the latter up and down.

11. A feed mechanism of the character described comprising a feed dog and its carrier, a drive shaft and an eccentric-crank actuator thereon, a pitman actuated by said actuator and,

a guide member in longitudinal sliding engagement with said pitman itself mounted for oscillation thereby, an operating connection from said pitman to one end of said carrier for moving the latter up and down, and means for also imparting horizontal to and fro movement to said carrier.

12. A feed mechanism of the character described comprising a feed dog and its carrier, a drive shaft and an eccentric-crank actuator thereon, a pitman actuated by said actuator and a guide member in longitudinal sliding engagement with said pitman itself mounted for oscillation thereby, a rocker having substantially upright and horizontal arms, a link connecting said upright arm to said pitman, a link connecting said horizontal arm to one end of said carrier for moving the latter up and down, and means for also imparting horizontal to and fro movement to said carrier.

NORMAN V. CHRISTENSEN. CLARENCE C. SMITH. GEORGE SAUER. 

